The paper introduces for scientific use a preface to the monograph “General and experimental biopotamology” by a Soviet hydrobiologist V. I. Zhadin (1896–1974) that was believed to be lost. Zhadin was known for his studies in the field of river biology, mostly specializing in the patterns of changes in river biocenoses, resulting from the construction of water reservoirs. In the 1960s, Vladimir Ivanovich began to work on this monograph that summarized the experience of his studies of many years on hydrobiological regime of the rivers. This book, however, had never been finished.

The preface to this book published here demonstrates the specifics of Zhadin’s scientific style. When recounting his findings, he rather focused on the description of processes and objects than on their quantitative expression. The style of the text resembles a preface to a popular science book rather than that to a scientific monograph. At the same time, Zhadin concisely formulates the program of comparative studies of the rivers that he himself had been implementing over more than 50 years of his scientific work. He intends to study biological patterns, including with the use of laboratory models of the rivers, which was an innovational approach to hydrobiology at the time, and points out to the fact that, of all water bodies, rivers are most susceptible to economic impact. Moreover, the processes caused by the hydrotechnical works and construction of water reservoirs change the rivers and river landscapes beyond recognition. Zhadin does not deny the necessity of river development but maintains that it should be done with care. In his opinion, river conservation is only possible if based on their in-depth research, which is what should be studied by biopotamology whose foundations were laid by Zhadin.